1. Field of the Invention
Example embodiments of the present invention relate to a method of forming a metal wiring in a semiconductor device. Other example embodiments of the present invention relate to a method of forming a metal wiring in a semiconductor device without a generation of a bridge between adjacent metal wirings.
2. Description of the Related Art
As information process apparatuses (e.g., computers) have become more widely used, semiconductor devices, employed in the information process apparatuses, have also been rapidly developed to have higher response speed and larger storage capacity. In semiconductor manufacturing technology, the integration degree, the reliability and the response speed of the semiconductor device have improved.
A metal wiring in a semiconductor device may have a reduced width in accordance with an increase in the integration degree of the semiconductor device. When the metal wiring has a reduced width, the metal wiring may not be properly formed without the generation of a failure (e.g., a bridge) between adjacent metal wirings. Further, the metal wiring in the highly integrated semiconductor device may have a higher electrical conductivity so that the metal wiring may be formed using a material having a lower specific resistance. The metal wiring employed in the semiconductor device may be formed using aluminum (Al), tungsten (W) and/or copper (Cu). Because aluminum has a specific resistance lower than that of tungsten and a metal pattern of aluminum may be more easily formed by a dry etching process in comparison with a metal pattern of copper, a contact plug and/or a conductive wiring of a current semiconductor device may be formed using aluminum.
In a conventional method of forming the metal wiring of a semiconductor device, an aluminum layer, a barrier metal layer and a mask layer may be formed on a substrate, and then, a resist pattern may be formed on the mask layer. The mask layer may be partially etched using the resist pattern so that a mask pattern is formed on the barrier metal layer. The barrier layer and the aluminum layer may be partially etched using the mask pattern to thereby form the metal wiring on the substrate.
FIGS. 1 and 2 are diagrams illustrating a conventional method of forming a metal wiring. Referring to FIG. 1, after an insulation interlayer 20 is formed on a substrate 10, an aluminum layer 22 and a barrier metal layer 24 may be successively formed on the insulating interlayer 20. A mask layer may be formed on the barrier metal layer 24. After a photoresist pattern 28 is formed on the mask layer, a mask pattern 26 may be formed on the barrier metal layer 24 using the photoresist pattern 28 as an etching mask.
When the mask pattern 26 is formed using the photoresist pattern 28, the barrier metal layer 24 and/or the aluminum layer 22 may be partially exposed so that polymers 29 generated in the etching process may be attached to a sidewall of the mask pattern 26 and the exposed portion of the barrier metal layer 24. The polymers 29 may be generated when the mask pattern 26 is formed using a photoresist pattern that may react relative to a light having a small wavelength for a smaller pattern.
When the polymers 29 are attached to the sidewall of the mask pattern 26 and the barrier metal layer 24, the aluminum layer 22 may not be properly etched due to the polymers 29. A bridge B as shown in FIG. 2 may be formed between adjacent metal wirings 25 after the formation of the metal wiring 25 having an aluminum layer pattern 22a and a barrier metal layer pattern 24a. This bridge B may cause an electrical failure, for example, an electrical short between the adjacent metal wirings 25.